JPH0218282Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a cylinder body for a silencer for an internal combustion engine, particularly to a multiple cylinder body having two or more double cylinders.

[Conventional technology]

The cylindrical body of a silencer is usually formed into a double or more multi-cylindrical structure using thin plates in consideration of moldability, durability, soundproofing, economic efficiency, etc. The forming means is a structure in which a single plate is rolled up multiple times (example 1978).
46820), the cylinder forming machine is continuously driven for the number of windings, which requires processing time.

In addition, the inner cylinder is formed of a plate made of a material that takes into account internal corrosion caused by chemical reactions with condensed water from exhaust gas and the exhaust gas purifying catalyst. Alternatively, depending on the region of destination, the outer cylinder may be made of a material that takes into account external corrosion due to salt damage or moisture damage, but this cannot be done with the multi-cylinder structure made of a single plate as described above. It is conceivable to join plates of different materials together and wind them in multiple layers, but this is labor intensive and takes time to form the cylinder.

Furthermore, the inner cylinder and outer cylinder are molded separately and fit together.
In the case where the joints of each cylinder are located on opposite sides (see Japanese Utility Model Application No. 59-32120), it is possible to obtain a cylinder made of different materials on the inside and outside, but it is structurally unsuitable for mass production.

[The problem that the idea attempts to solve]

In light of the above-mentioned conventional examples, the present invention aims to shorten the cylinder molding time and to obtain a multi-cylindrical structure of a silencer that can easily obtain a structure made of different materials for the inner and outer cylinders.

[Means to solve the problem]

In the present invention, the overlap distance α is smaller than the inner circumference l of the product cylinder.
The length of the short plate 2 and the required number of windings l
The two different plates 2 and 3 are overlapped with the long plate 3 which is longer by the overlap margin α 2 than ₂ , and the winding start ends are almost coincident and rolled at the same time, and the winding end of the long plate 3 is wrapped around the lower cylinder body. This is the cylindrical body of a silencer that is fixed.

[Effect]

It is easy to operate because it has a cylindrical structure in which two plates 3 and 2 of different lengths and short sides are stacked on top of each other and rolled and formed at the same time with the winding start ends substantially coincident. In the case of a double cylinder, the cylinder molding machine only needs to be rotated by one rotation and the length of the overlap margin α ₂ of the long plate 3, so the molding time is shortened. At the end of winding each of the inner and outer cylinders, the overlap margin α, α is ₂ minutes, so
No gas leaks. A corrosion-resistant cylindrical body in which the inner and outer circumferential surfaces of the cylinder are made of different materials can be easily obtained.

〔Example〕

Examples will be described with reference to the drawings. Fig. 1 shows an example of a muffler cylinder 1, and Fig. 2 shows a short plate 2 that is longer than the inner circumference l when rolled up into a cylinder by an overlap margin α (for example, 10-odd mm), and the necessary Number of turns length l2
FIG. 3 is an explanatory diagram showing a state in which a long plate 3, which is longer by an overlap margin α ₂ , is overlapped and the winding start ends of both plates 2 and 3 are substantially aligned. At that time, in order to prevent the inner end cut surface 3 ₃ of the long plate 3 forming the second outer layer from coming into contact with the exhaust gas, the short plate 2 forming the inner layer is
The starting end side of is slightly lengthened by α ₁ to form a step,
Cover the cut surface ₃ . It is also better to spot-weld the two plates 2 and 3 at the winding start end.

The two plates 2 and 3 prepared as described above are rolled together as shown by the chain line from the winding start end using a known rolling means consisting of a mandrel, a pressure roller, etc., and the long plates 3 are overlapped at the end of the winding. The terminal end 6 of the width α ₂ is welded to the cylindrical surface 3 of the lower layer.

Figure 3 is a cross-sectional view of an example of a double cylinder, with two short plates.
The long plates 3 go around once to form an inner cylinder, and the long plates 3 overlap each other with the starting end of the long plate 3 sandwiched therebetween at an overlapping margin α. The long board 3 is
The outer cylinder 3 is formed, and the outer cylinder 3 is further wound by an overlap margin α ₂ , and is welded 6 to the lower layer 3 while covering the end of the winding of the inner cylinder 2.

If internal corrosion is to be considered, the corrosion-resistant material may be layered on the inside, and the outer material may be made of another inexpensive material. On the other hand, if external corrosion is to be taken into consideration, the plates can be used with the inside and outside reversed.

FIG. 4 shows an example of a triple cylinder body in which two layers 3 ₁ and 3 ₂ are formed on the outer periphery of the inner cylinder 2 using the longer plates 3, and in this manner a desired multiple structure can be obtained.

FIG. 5 shows an example of applying the technology of the present invention and sandwiching a heat insulating/sound insulating material 5 such as asbestos or glass wool between the plates 2 and 3 forming the inner and outer cylinders and wrapping them together. A cylindrical body that is highly safe against temperature increases associated with exhaust gas purification and has a low temperature can also be easily produced.

Figure 6 shows the long plate 3 being rolled in,
An example is shown in which the short plate 2 is used as an intermediate cylinder, and the long plate 3 forms an inner cylinder 3 ₁ and an outer cylinder 3 ₂ inside and outside. It is suitable for the case where corrosion-resistant material is used for both the inside and outside of the cylinder, and the intermediate cylinder 2 can be made of an inexpensive material to reduce costs.

[Effect of idea]

According to the present invention, as described in the section of the above-mentioned function, a double or more multiple cylinder body made of two different plate materials can be easily obtained by shortening the processing time. A multiple cylinder body in which the inner cylinder and the outer cylinder are made of different materials can be easily obtained. Since an overlap margin is formed at the end of the winding of the outer cylinder that is longer than the circumference, there is an advantage that there is no risk of gas leakage.

[Brief explanation of the drawing]

Fig. 1 is a front view of the muffler cylinder to which the present invention is applied, Fig. 2 is an explanatory view of the material plate of the invention, Fig. 3 is a cross-sectional view of the double cylinder body of the invention, and Fig. 4 5 is a cross-sectional view of a triple cylinder, FIG. 5 is an explanatory diagram of a case in which a cylinder containing a heat insulating/sound insulating material is formed, and FIG. Cross section. DESCRIPTION OF SYMBOLS 1... Silencer cylinder body, 2... Short plate, 3... Long plate, α, α ₂ ... Overlapping margin, 6... End fixing part of plate 3.

Claims (1)

[Scope of utility model registration request] The cylindrical body of an exhaust system muffler for an internal combustion engine, which has a multilayer structure, consists of a short plate that is longer than the inner circumference of the product cylindrical body by the amount of overlap, and a long plate that is longer than the required number of windings by the amount of overlap. A muffler cylinder made by overlapping two different plates, rolling them together at the same time with their starting ends almost aligned, and fixing the winding end of the long plate to the lower cylinder.